In a small bowl, combine chicken, cheese, cumin and jalapeño, if desired. Warm a medium skillet over medium heat. Spread chicken mixture over 1 tortilla and top with the other, pressing down with a spatula. Cook until golden brown and crispy, about 4 minutes. Carefully flip and cook 3 to 4 minutes longer. Let cool completely before packing to keep it from getting soggy. Cut into six wedges; send along with a small container of salsa.